Piston-valve



D. MORE.

PISTON VALVE.

APPLICATION FILED FEB. 12, 1919.

Patented Nov. 9, 1 920.

David wit/444240 UNITED STATES PA EN OFFICE.

nn'vm MORE, or antenna NEBRASKA.

PIlISTON-VAIN'E.

Specification of Letters Patent.

Patented Nov. 9, 1920.

Application filed February 12 1919. Serial a. 276,587. 7

To all whom it may concern Be it known that I, DAVID MORE, a citizen of the United States, residing at Omaha, in

the county of Douglas and State of Nebraska, have invented new and useful Improvements in Piston-,Valves, of which the following is a specification.

This invention relates to piston valves such as are commonly employed in locomo tive steam engines- The object of the invention is to provide a novel arrangement of packing rings on the follower heads of the piston valve body, whereby one of the pack I ing rings is permitted to have a limited valve.

lateral movement or a-movement to a lim-' ited extent longitudinally of the valve body, means in the form of an additional packing ring being employed to-protect the said laterally movable ring by preventing the steam pressure from acting thereonat certain points in the movement of the piston By means of the improved construction hereinafter described and illustrated in the accompanying drawings, is a short cut off which steam port is uncovered for a longer a .period of time with a corresponding reduction of compression and a proportionate increase inthe expansive use of the steam. Also during the exhaust position of the valve, the port is 'left uncovered for a greater period of time thus relieving compression, and a free and less opposed movement of the piston is obtained.

- With the above and other objects in view,

the invention consists in the novel construcmainly of the ordinary well known construction embodying the thimble or main body portion 6 and the heads .7 at the opposite ends thereof, the heads being held in fixed relation to the body 6 by means of the valve .stem 8 having a shoulder 9and a nut-10 between which the heads 7 are clamped.

Each head 7 is rabbeted as shown to receive the usual bull ring 11- and said bull rin is in turn rabbeted to receive the split pac ing rings 12 and13. Up to this point the construction hereinabove described cor-- responds with the present day standard piston valve as used in locomotive steam en ines.

carrying out the present invention, I

make the groove 14 in which the packing ring 13 is placed, of greater width than that portion of thering which lies. therein so that the ring is adapted to move laterally in the groove 14 or longitudinally with respect to the length of the piston valve as a Whole. Each packing. ring 13 has a floating movement 'for' the purpose of gaining a longer expansive use of the steam on the release movement of the valve, and a longer opening on the closing movement of the valve.

When the valve is moved in either direction, the rings 13 are moved by the valve, the frictional contact between the rings and the bushing 2 having a tendency to hold the rings on the return movement in either direction. The rings 13 are of less width than the grooves in which they are arranged, and hence the said rings are able to float from one side of the groove to the other on movement of the valve to function as described- 41. e., to hold steam a longer time in the cylinder on the opening movement of the valve, and to hold the ports 3 open lo'nger'to allow compression'to start,

on the closing movement of the valve.

At 15 are intermediate rings Each ring 15 serves to protect the packingring 13 ad jacent thereto from live steam, the adjacent L line when the valve begins to open, if the ring 15 were not employed, steam would pass under the rim 12 around to the back side and would pus the'ring 13 to the outer rin 12 being of a less width than theport edge of the groove. Such action, however, back and forth movements of the piston 10 iseffectively prevented by the employment valve, in combination With ,an auxiliary of the ring 15. packing ring back of and spaced from the a I claim first-named ring, and a third ring interme- Y A piston valve having a groove and a diate of the first and second rings to propaeking ring mounted in the groove, said tect the first ring from live steam. 15'

groove being of greater Width than that por- In testimony whereof I aflix my signature. 1

tion of the ring Which lies therein, whereby said ring is adapted to shift laterally in the DAVID MORE. 

